全文获取类型
收费全文 | 423157篇 |
免费 | 27626篇 |
国内免费 | 4178篇 |
专业分类
耳鼻咽喉 | 5653篇 |
儿科学 | 9019篇 |
妇产科学 | 10911篇 |
基础医学 | 58456篇 |
口腔科学 | 12604篇 |
临床医学 | 34749篇 |
内科学 | 86036篇 |
皮肤病学 | 9382篇 |
神经病学 | 30637篇 |
特种医学 | 15488篇 |
外国民族医学 | 95篇 |
外科学 | 66594篇 |
综合类 | 13766篇 |
现状与发展 | 6篇 |
一般理论 | 111篇 |
预防医学 | 20517篇 |
眼科学 | 10986篇 |
药学 | 34536篇 |
20篇 | |
中国医学 | 3271篇 |
肿瘤学 | 32124篇 |
出版年
2021年 | 4536篇 |
2020年 | 2903篇 |
2019年 | 4063篇 |
2018年 | 6037篇 |
2017年 | 4706篇 |
2016年 | 4803篇 |
2015年 | 5654篇 |
2014年 | 7786篇 |
2013年 | 9553篇 |
2012年 | 13407篇 |
2011年 | 13609篇 |
2010年 | 8107篇 |
2009年 | 7494篇 |
2008年 | 11917篇 |
2007年 | 12783篇 |
2006年 | 12594篇 |
2005年 | 11720篇 |
2004年 | 10650篇 |
2003年 | 10161篇 |
2002年 | 9667篇 |
2001年 | 28999篇 |
2000年 | 29494篇 |
1999年 | 24410篇 |
1998年 | 5662篇 |
1997年 | 4682篇 |
1996年 | 4173篇 |
1995年 | 3817篇 |
1994年 | 3383篇 |
1993年 | 3048篇 |
1992年 | 16373篇 |
1991年 | 15104篇 |
1990年 | 14430篇 |
1989年 | 14212篇 |
1988年 | 12797篇 |
1987年 | 12271篇 |
1986年 | 11279篇 |
1985年 | 10473篇 |
1984年 | 7041篇 |
1983年 | 5689篇 |
1982年 | 2787篇 |
1979年 | 5546篇 |
1978年 | 3408篇 |
1977年 | 3035篇 |
1975年 | 2688篇 |
1974年 | 3132篇 |
1973年 | 2917篇 |
1972年 | 2884篇 |
1971年 | 2807篇 |
1970年 | 2544篇 |
1969年 | 2581篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
N Kohashi N Iida Y Kumon S Inoue 《Nihon Ronen Igakkai zasshi. Japanese journal of geriatrics》1992,29(10):753-757
In order to evaluate the quality of life (QOL) in hypertensive outpatients, we selected 78 patients with hypertension of various degrees of severity (WHO Classification I: 29 cases, II: 15, III: 34), 59 not ill healthy persons (N1) and 22 normotensive outpatients (N2) aged at 50 years and over, using the self-completed questionnaire (QUIK) which we developed. QUIK covers four domains including physical functioning (20 questions), emotional adjustment (10), interpersonal relationships (10) and attitudes toward life (10) totaling 50 questions. In this study the internal consistency of QUIK was alpha = 0.95 by the Kuder-Richardson formula 20 and it's repeatability was r = 0.89 by the Spearman-Brown formula. The QOL in hypertensive outpatients was definitely worse in terms of total score (N1 5.1 +/- 4.4 vs WHO II 9.3 +/- 7.2 and III 12.1 +/- 5.6, p < 0.05), for physical functioning (N1 2.5 +/- 2.1 vs WHO I 3.7 +/- 2.8, II 4.7 +/- 3.8, III 5.4 +/- 2.8 p < 0.05), for emotional adjustment (N1 1.2 +/- 1.4 vs WHO III 2.3 +/- 1.7, p < 0.01), for interpersonal relationships (N1 0.8 +/- 1.3 vs WHO III 1.6 +/- 1.5, p < 0.01) and for attitudes toward life (N1 0.7 +/- 1.2 vs WHO III 2.7 +/- 2.0 p < 0.01). The total QUIK score increased according to the severity of symptoms (WHO I 5.8 +/- 4.4, WHO II 9.3 +/- 7.2 and WHO III 12.1 +/- 5.6), respectively. The total score of WHO I was significantly lower compared with that of WHO III (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
992.
G. M. Brieger M. Mongelli L. Y. Hin T. K. H. Chung 《International urogynecology journal》1997,8(4):191-195
The epidemiology of urinary dysfunction in a Chinese population living in Hong Kong was investigated. Fifteen hundred ethnic
Chinese women answered a telephone questionnaire including symptoms of urinary dysfunction, anthropometric measurements, obstetric
history and place of birth. The relative predictive value of these factors was analyzed using logistic regression. The prevalence
of urinary dysfunction was 13%. Ten percent reported stress incontinence, and 4% had urgency or urge incontinence. The strongest
predictor was place of birth, with women born in mainland China having the highest prevalence of pure stress incontinence
(OR 1.33, CI 1.1–1.6). For the symptoms of detrusor instability age was the strongest predictor, with women over 50 years
being at greater risk (OR 2.8, CI 1.6–5.0). Contrary to earlier beliefs, urinary dysfunction in Chinese women is as common
as in Caucasian women. Place of birth is the strongest predictor for pure stress incontinence, with women born in mainland
China being at greater risk. This suggests that environmental factors in early life have a differential effect on the development
of urinary incontinence.
EDITORIAL COMMENT: Taiwan Chinese women have a comparable prevalence of urinary dysfunction with Hong Kong Chinese women.
A survey representing a multistage sample of 82 678 women aged 18 years or older was conducted in the Taipei area from January
to June 1993. A total of 818 cases were interviewed by trained students. One hundred and eighty-nine (23.1%) of the respondents
reported having had some degree of incontinence in the preceding 12 months, 28 (3.4%) reporting regular incontinence. Most
presented with stress urinary incontinence, whereas urge incontinence and mixed incontinence were more commonly seen in the
elderly group (aged 60 years or older). The risk factors for urinary incontinence included age, number of vaginal deliveries
(>3), number of abortions (>2) and maternal history of incontinence. Voiding symptoms (irritative or obstructive) and constipation
were significantly more prevalent among respondents with incontinence than those without (P<0.001). This evidence also indicates that the long-held belief that Chinese women have a much lower prevalence of urinary
dysfunction than western women has all but ended. 相似文献
993.
Verna W. Y. Yiu Robert P. Dluhy Richard P. Lifton Lisa M. Guay-Woodford 《Pediatric nephrology (Berlin, Germany)》1997,11(3):343-346
In evaluating hypertensive children and adolescents, the etiological considerations should include a set of inherited disorders
that share very low plasma renin activity (PRA) as a common feature. In particular among these disorders, glucocorticoid remediable
aldosteronism (GRA) appears to be emerging as an important etiology of hypertension in the pediatric population. We report
the evaluation of a 9-year-old Caucasian girl who presented with severe hypertension and a strong family history of early-onset
hypertension. Her suppressed PRA, her family history, and her failure to respond to conventional antihypertensive therapy
raised GRA as a potential etiology. The diagnosis was confirmed by an elevated ratio of urinary 18-oxotetrahydrocortisol to
urinary tetrahydroaldosterone and genetic testing, which demonstrated the chimeric gene duplication. The molecular pathogenesis
of GRA and the clinical implications are reviewed.
Received May 15, 1996; received in revised form and accepted September 16, 1996 相似文献
994.
Pallav J Shah Manoj Durairaj Ian Gordon John Fuller Alex Rosalion Siven Seevanayagam James Tatoulis Brian F Buxton 《European journal of cardio-thoracic surgery》2004,26(1):118-124
OBJECTIVE: The purpose is to define factors influencing long-term patency of the internal thoracic artery (ITA) to optimize the operative strategy. METHODS: 1482 left internal thoracic artery (LITA) and 636 right internal thoracic artery (RITA) symptom-directed angiograms were studied in 1434 patients. Data were prospectively collected from patients who had primary coronary artery bypass surgery during the period 1982-2002. The mean age of patients was 59 years; 85% were male. The mean period from operation to re-angiogram was 80 months. LITA was grafted to left anterior descending coronary artery (LAD) in 82% of cases, RITA to right coronary artery (RCA) in 40% and circumflex artery in 35% of cases. Graft failure was defined as > or =80% stenosis. RESULTS: 96.3% of LITA and 88.1% of RITA grafts were patent. No patient variables were significantly associated with graft patency (age, gender, diabetes, hypertension, LVEF, NYHA, AMI). Target coronary artery was associated with patency of both LITA and RITA grafts with maximum patency when grafted to LAD (P = 0.02) RITA had the worst patency to RCA, patency for the left system was identical to LITA. Proximal anastomosis to aorta (free RITA) had significantly better patency when compared with in situ RITA to RCA system (P = 0.005) while similar patency when grafted to left system. ITA diameter and target artery diameter were not associated with graft patency. Recent operations had better RITA patency (P = 0.03). The interval from operation to angiogram was not associated with ITA patency (96% patency for LITA and 88% patency for RITA, remained stable when studied at <1, 1-4, 5-9, 10-14 and >15 years). CONCLUSIONS: Even in a patient cohort that had adverse symptoms, excellent LITA and RITA patency was achieved which almost remained constant through all time intervals studied. 相似文献
995.
T. Vander M. Medvedovsky I. Shelef L. Duchano A. Tomer Y. Herishanu 《European journal of neurology》2004,11(8):569-571
While a dural sinus thrombosis (DST), is a well-known consequence of the use of oral contraceptives, the role of hormone replacement therapy (HRT) in DST was not previously evaluated. We report two postmenopausal women, presenting with DST under HRT. Antiphospholipid antibodies in one case and borderline protein S deficiency in another were diagnosed. Only five cases of DST under HRT were previously reported and in two of them additional prothrombotic risk factors were found. According to these and previous cases, HRT is not an independent risk factor for DST. 相似文献
996.
Y Magnusson G Wallukat J G Guillet A Hjalmarson J Hoebeke 《Journal of autoimmunity》1991,4(6):893-905
A synthetic peptide corresponding to the second extracellular loop of the beta 1-adrenergic receptor was used as an antigen for antibody production in three rabbits. Antibodies of high titers were obtained in all rabbits. Only one rabbit yielded antibodies which decreased radioligand binding on the receptor in a similar way to that described for autoantibodies in patients with dilated cardiomyopathy. These antibodies recognized the receptor protein in immunoblots. Epitope mapping indicated that the N-terminal sequence of the loop used as antigen was the target of the major antigen fraction. Incubation of antibodies with C6 glioma cell membranes or inner membranes of E. coli, which express the human beta 1-adrenergic receptor, resulted in a decrease in number of radioligand binding sites. This decrease was dependent on the concentration of antibody and of Mg++ ions. It was not affected by the GTP analog GppNHp or the beta 1 subtype-specific antagonist metoprolol. The agonist, isoproterenol, also induced a decrease but the effects of antibody and agonist were not additive. These results suggest that the antibodies induce a Mg(++)-dependent, 'active', labile conformation of the receptor, independent from coupling to the GTP regulatory protein, but similar to that induced by the agonist isoproterenol. This interpretation was corroborated by the beta 1-adrenergic receptor agonist-like effect of the antibodies on cardiomyocytes in culture. 相似文献
997.
998.
不同类型高危儿早期干预的临床研究 总被引:4,自引:0,他引:4
目的 探索早期干预对窒息、高胆、早产三类高危儿智力发育改善的效果,寻找更合适的早期干预措施。方法 将三类高危儿分为干预组及对照组,同时随机选取正常对照组进行随访。干预组采用鲍秀兰教授“0~3岁”早期干预方案训练,各组均在6个月、1岁时分别采用婴幼儿智能发育量表(CDCC)进行智力发育测评,结果用MDI、PDI表示。结果 (1)6个月龄时MDI各干预组与对照组间有显著性差异,窒息组、早产组与正常组间亦有显著性差异;高胆组与正常组间无差异;PDI窒息组中干预组与对照组之间有显著差异(P<0.01),高胆组、早产组均无差异(P>0.05)。(2)1岁时MDI和PDI结果一致,干预组与对照组间比较窒息组、高胆组有显著差异,早产组无差异;窒息组、高胆组干预组与正常组比较无差异,对照组和早产组与正常组比较均有显著差异(P<0.01)。(3)所有干预组测评分值均高于对照组,6个月与1岁之间比较有显著差异,各观察组间比较有显著性差异(P<0.01)。结论 三类高危儿早期干预效果差异较大,干预组均较对照组分值高,早期干预有改善智力发育的作用;三类高危儿中,窒息组、高胆组效果最好,均达到或超过正常水平。所有未干预组均不及正常水平;早期干预对足月高危儿效果显著,对早产儿欠佳,远期效果尚需进一步随访观察。 相似文献
999.
TPA (12-O-tetradecanoylphorbol-13-acetate), a potent tumor promoter, has been shown to stimulate or inhibit cell growth depending on the cell type investigated. We recently found that RT101 cells, a transformed mouse JB6 epidermal cell line, acquired a greater growth inhibition response to TPA during conventional subcultivation. The growth of low-passage RT101 cells was slightly inhibited by TPA in monolayer culture but stimulated in soft agar. In contrast, the growth of high-passage cells was greatly inhibited by TPA in both monolayer culture and in soft agar. Inhibition was dose dependent, directly correlated with protein kinase C-activating activities of tumor promoters, and was found to be reversible. TPA-treated high-passage cells were greatly reduced in volume, showed extensive abnormal mitoses, and were more susceptible to detachment. High-passage cells were also found to be less tumorigenic as indicated by in vivo tumorigenicity assay in nude mice. TPA treatment rendered cells still less tumorigenic in the case of both cell lines. The mechanism for acquisition of increased sensitivity to TPA of RT101 cells during subculture was investigated; it involved nonrandom DNA damage and detachment of nonviable cells. The results suggest the possibility that early-passage RT101 cells contained two subpopulations, one TPA-sensitive and one TPA-resistant population. Conventional subcultivation may have selected for the former subpopulation. The sensitive subpopulation may have been irreversibly inhibited as a result of TPA-induced cell killing, possibly apoptosis. 相似文献
1000.
P Y Chang K C Lin C Y Chuang C R Wang M Y Chen W C Hsieh G R Wang D L Cheng K S Chang Y C Ko 《Asian Pacific journal of allergy and immunology / launched by the Allergy and Immunology Society of Thailand》1992,10(1):65-68
From May 1, 1985 to December 31, 1991, a total of 4,962,707 serum samples from 8 population groups in Taiwan were tested for anti-human immunodeficiency virus type 1 (anti-HIV-1). In total, 256 samples were seropositive; of these individuals, 43 developed acquired immunodeficiency syndrome (AIDS): 29 were homosexuals; 5 were hemophiliacs; 8 were heterosexuals and 1 was of unknown risk. Although the prevalence of HIV-1 infection and AIDS remains low compared with other countries, since 1988 the increase has been rapid. Before 1977 the majority were homosexuals and hemophiliacs; thereafter the risk groups diversified, with a trend away from homosexuals and hemophiliacs towards heterosexuals and intravenous drug abusers (IVDAs). A few patients have caused serious social problems for the public, health care workers and families. Active community efforts are needed to achieve future success in the control of HIV-1 infection and AIDS in Taiwan. 相似文献